Circuit breaker



Aug. 9; 1938. R. N. ROWE 2,125,412

CIRCUIT BREAKER Filed Jan. 12, 1937 2 Sheets-Sheet l ENVENTOR BY U.

Aug. 9, 1938. E 2,126,412

C IRCUIT BREAKER Filed Jan. 12, 1937 2 Sheets-Sheet 2 INVENTORflay/W017i 730100 Patented Aug. 9, 1938 UNITED STATES PATENT OFFICECIRCUIT BREAKER Raymond N. Rowe, Plainville, Conn, assignor to TheTrumbull Electric Manufacturing Company, Plainville, Conn, a corporationoi. Connecticut Application January 12, 1937, Serial No. 120.159

Claims. (Cl. 200-116) is simple in construction and reliable inoperation.

Another object is to provide a device which will automatically open thecircuit even when the operating handle or finger piece is held in theolosedcircuit position.

Another object is to provide such a device which can be readily resetafter automatic trip- Another object is to provide such a device inwhich the point of automatic opening can be readily adjusted.

Another object is to provide a construction which will require only asingle spring to open the circuit with a snap action when actuatedmanually or automatically and which will close the circuit with a snapaction when actuated manually.

The accompanying two sheets of drawings show two forms of the invention.

Fig. 1 is a side view of the preferred form of mechanism embodying myinvention, the parts being shown in the normal open circuit or of!position.

Fig. 2 is a similar view showing the parts in the closed circuit or onpositiom Fig. 31s a similar view showing the parts in the openacircuitposition-resulting from the automatic thermostatic release action.

Fig. 4 is a vertical sectional view on the plane of the line 4-4 of Fig.l.

Fig. 5 is an exploded perspective view showing the principal parts ofthe mechanism. I

Fig. 6 is a sectional view of a modified form of mechanism embodying theinvention enclosed in an lnsulating'housing and showing the parts in theopen circuit or 011 position.

Fig. '7 is a side view of the mechanism of Fig. 6 with the parts in theclosed circuit or on position.

Fig. 8 is a side view of the same parts in the open circuit positionresulting from the automatic thermostatic release.

Fig. 9 is a perspective view of the movable elements of the form shownin Figs. 6, '7 and 8.

Fig. 10 is a perspective view showing the housing and actuating memberof a unit embodying my invention.

The mechanism of the circuit breaker of the switch is preferablyenclosed within a housing consisting of a base ill and an upper part i0suitably secured together and having suitable circuit terminals for theconnection of conductors.

All of the moving parts are carried by a frame I i which is suitablysecured to the base I0. There are three movable elements all supporteddirectly or indirectly by this frame. These consist of the main switchlever or contact member i2, the actu-. ating arm or lever i3 and thekick-off lever it. The bimetallic thermostatic arm i5 is mounted on thesupporting base iii. A flexible lead i5 connects the arm i5 and thecontact l2. A single spring l6 connects the switch member i2 and theactuating member i3.

Stationary contact I! is located in a position to be engaged by thecontact of the switch member i2. The lever i2 is pivoted or hinged in anopen notch or bearing iii in the underside of the upper part of theframe ii. The movable end of switch member I! in. the open circuitposition 7 rests against an abutment IS in the frame.

The kick-off member I4 is pivoted in lugs 20 which are bent up from oneside of the frame. The actuating arm I3 is hinged on pintles 2| whichextend from the opposite sides of the kickoff member ll. The base of theframe ii has an abutment or abutments such as 22 against which a heelorheels such as 23 rests in the normal open circuit position of theparts. The upper arm of the frame Ii is provided with stop shoulders 24and 25 to limit the movement of the actuating arm i3. The spring i6 isconnected to cross piece 2'! in the switch member l2 and to a pin 26car% rled by the actuating arm iii. The kick-off lever H has a finger 28which is adapted to engage a part 28 of the switch member l2 when thether-] mostatlc member i5 releases the kick-off lever I4 The kick-offlever is provided with an adjustable projection 30 which is in the formof a screw member adapted to be moved back and forth in the kick-offmember to adjust the point at which the warping of the thermostatic armIt) becomes 7 effective to release the kick-off lever.

The actuating lever is provided with a suitable finger piece 3i tofacilitate its manual operation. This finger piece has a shaft 32 whichprojects through a slot in the top of the housing and the top of thisslot is kept closed by an arcshaped member 33. The finger piece 3! andthe extension 33 may be held in place in any suitable manner. Inside ofthe housing is an are shaped member 33' which is mounted to move withthe shaft 32 of the finger piece 3|. It may be The upper part of theframe is provided with a slot 35 and the switch member I2 is providedwith a slot 36 to permit of the swinging motion of the spring I6.

The normal manual operation of the switch or circuit breaker isaccomplished by simply moving the finger piece 3| from one side to theother so that the actuating arm |3 swings about the pivot 2| which isnormally stationary. This action is similar to that of the well knownsnap action or toggle mechanism.

When the parts are in the closed circuit position of Fig. 2 and thethermostatic member |5 is warped suiiiciently by reason of heat createdby the resistance to current passing through it, the upper end of themember |5 will be moved to the right out of the way of the screw tip 30.As a result the spring l6 which is pulling down against the pin 25 onthe actuating lever will cause pressure to be applied through theactuating arm |3 against the pintle bearings 2| which are almost in linewith the center of the pin 26, and the crosspiece 21. This immediatelythrows the actuating arm |3 toward the left and throws the switch memberl2 toward the left until the movable end of the switch member strikestheabutment l9 and the heel of the actuating lever 23 strikes the abutment22 and the parts assume the position shown in Fig. 3, where the fingerpiece 3| is in a position approximately midway between the stopshoulders 24 and 25 which will be called a tripped position.

It will be seen that the actuating lever in moving from the position ofFig. 2 to the position of Fig. 3 has moved radially inward as thepintles 2| on the kick-on member |4 swing about the hinge or pivot 20.This opening of the circuit will occur even though an attempt is made tohold the actuating lever l3 in the on position. In this event theactuating lever will remain in approximately the same angular positionof Fig. 2 except that it will move radially inward to a positionintermediate that of Figs. 2 and 3.

To re-set the circuit breaker it is simply necessary to move theactuating lever from the position of Fig. 3 to the oiT position ofFig. 1. In this action the actuating lever swings about the trip of theheel 23 and the pintles 2| are lifted so as to tilt the kick-off member|4 about its hinge point 20 until the thermostatic member l5 can snapbeneath the projection 30 and hold the kickoff member in the normal offposition.

The circuit of the switch may then be closed by simply moving theactuating lever from the position of Fig. 1 to the position of Fig. 2 atwhich time the actuating lever swings about the pintles 2| which are nowstationary.

From the foregoing it will be seen that the actuating lever has threepositions, the open circult or off position of Fig. 1, the closedcircuit or on position of Fig. 2 and the intermediate or trippedposition of Fig. 3.

The lever M and the thermostatic arm |5 constitute one form of currentresponsive device or means for normally holding 'the operating memberI3. in an operating position against the bias of the spring IE butadapted to release the operating member and break the circuit upon theoccurrence of a predetermined overload current in the circuit controlledby the contact or switch arm l2.

scribed but the action is much the same. The mechanism is enclosed in ahousing having a base IO and a top ID. ,The switch members 40 and 4| arelike members I? and Hi respectively. Stationary contact 43 is connectedto the supporting bushing 42 which may be connected to a bus bar 43 orother exterior circuit terminal. The frame member 44 is fixed to thebase and has a transverse bearing 45 for the hinged switch contactmember 4|. The latter is connected by a flexible lead 46 to the outerend of the bimetallic arm 41 whose lower end is secured to a support 48.The terminal member 49 carries the support 48 which is adjustable byscrew 50 to vary the point of release of the thermostatic member 41. Themember 49 has an external circuit connection 5|.

The kick-off member 52 is hinged on the same pin 45 which provides abearing for the switch member 4|. This kick-off member has an insulatingpiece 53 which engages the hook on the outer end of the arm 41.

A wire yoke 54 is supported on the opposite arm of the kick-off memberand has hinge bearings 55 which support the actuator 56. latter piecehas a lug 51 to which the upper end of spring 58 is connected. The lowerend of spring 58 is connected to the eye 59 on the switch member 4| sothat when the actuator is moved from the oii position of Fig. 6 to the"on position of Fig. 7 the switch member will snap on and vice versa thecircuit will be opened when the actuator is moved from right to left.

The finger piece 60 has a shaft 5| which extends into an opening in theupper end of the actuator 56. An outer are shaped piece 62 and an innerone 63 serve to keep the slot 64 closed. The finger piece 60 and itsextension 62 may be secured on the shaft 6| in any suitable manner. Thefinger piece 60 and the member 63 may be held in place in any suitablemanner.

When the parts are in the closed circuit position shown in Fig. 7 andthe arm 41 is warped so as the release the kick-off member 52 thetension of the spring 58 pulls down on the actuator.

56 which in turn pulls down on the right end of the kick-off lever 52and tilts the lever 52 and at the same time snaps the switch member 4|to the open circuit or ofi position. The inward or downward motion ofthe actuator is permitted by reason of the sliding connection of theshaft 6| in the outer end of the actuator.

When the arm 41 has cooled oiT and resumes its normal position theswitch may be reset by swinging the actuator toward the left (Fig. 8),the trip position. The inclined lug 51 slides out- Wardly over theinclined edge 65 of the insulator 53 until the insulator snaps under theupper hooked end of the thermostatic arm 41 whereupon the switch may beactuated manually in the usual manner. It will be seen that a singlespring suffices to effect the necessary snap action when the switch isactuated automatically as well as manually.

It should be noted that in both forms of the device, the placing of themoving contact, kickoff piece, and spring within the frame, with theU-shaped actuator outside of the frame and straddling the other partsmakes it possible to confine the mechanism to a very small space.

During the trip position the kick-ofi piece and the frame in both formscooperate to limit arcuate movement of the actuator, thus indicating thetripped position by the location of the. handie. In both forms movementof the handle to This g full "01? position will move the actuatorarouately and this will pivot the kick-oft piece to reset the breaker.Resetting movement of the kick-01f piece will force the actuatorradially outward into its position for normal operation. The preferredform uses the heel 23 to obtain a very strong direct lever actionbetween the actuator and the kick-oil piece for the resetting movement.The form shown in Figs. 6 through 9 uses direct camming action of thelug 51 to accomplish positive resetting.

I claim:

1. A circuit breaker having a frame, a contact lever hinged to theframe, a kick-off member hinged to said frame, a current responsive.member normally restraining movement of said kick-off member, anactuating lever hinged to said kick-off member and a spring connecting.

said contact lever and said actuating lever and serving to snap thecontact lever when the actuating lever is manually moved to the ofP' andon positions respectively to open and close the circuit and serving toopen the circuit andmove the actuating member to a position intermediatethe usual on and off position when the current responsive memberreleases the kick-off member.

2. In a circuit breaker device, a switch contact member hinged near oneside of the'device, a kick-off lever hinged near the opposite side ofthe device, an actuator hinged to and movable with the kick-off lever, aspring connecting the actuator and the switch contact member, a currentresponsive member normally restraining the movement of the kick-offmember and means moved with the kick-off member to move the switchcontact member when the current responsive member releases the kick-offmember.

3. In a circuit breaker, a hinged switch contact member, a hingedkick-off lever, an actuator hinged to and movable with the kick-offlever, a spring connecting the actuator and the switch contact member, acurrent responsive member normally restraining the movement of thekick-off member and a projection on the kick-ofi member to engage theswitch contact member when the current responsive member releases thekick-off member.

4. A circuit breaker having a frame, a contact lever hinged to theframe, a kick-off member hinged to said frame, a current responsivemember normally restraining movement of said kick-off member, anactuator hinged to said kick-off member and a spring connecting saidcontact lever and said actuator and serving to snap the contact leverwhen the actuator is manually moved to the off and on positionsrespectively to open and close the circuit and serving to open thecircuit and move the actuator to a position intermediate the usual 011"and off position when the current responsive member releases thekick-ofi' member, saidfr'ame having stops for said actuator and saidcontact lever.

5. In a circuit breaker device, a switch 6ontact member hinged near oneside of the device, a kick-off lever hinged near the opposite side ofthe device, an actuator hinged to and movable with the kick-ofi lever, aspring connecting the actuator and the switch contact member, a currentresponsive member normally restraining the movement of the kick-offmember and means moved with the kick-off member to move the switchcontact member when the current responsive member releases the kick-oifmember, said kick-off member and spring serving to move the actuator toa tripped position when the kickoff member is released.

6. In a circuit breaker, a hinged switch contact member, a hingedkick-off lever, an actuator hinged to and movable with the kick-offlever, a spring connecting the actuator and the switch contact member, acurrent responsive member normally restraining the movement of thekick-oh member and. a projection on the kick-off member to engage theswitch contact member when the current responsive member releases thekick-off member, said kick-off member and spring serving to move theactuator to a tripped position when the kick-off member is released. I

7. In a circuit breaker, a hinged switch contact member, a hingedkick-oil lever, an actuator hinged to and movable with the kick-offlever, a spring connecting the actuator and switch contact member, and acurrent 'respon sive member normally restraining the movement of thekick-off member, said contact member, kick-off lever and actuator beingmovable in the same vertical plane.

8. A circuit breaker comprising a support, switch member pivoted on saidsupport, an operating member, a spring connected to said switch memberand said operating member for biasing said switch member to a closedcircuit position and said operating member to a predetermined position,supporting means movable upon a change in current conditions for holdingsaid operating member in an operating position against its bias to saidpredetermined position, and means responsive to movement of saidoperating member to said predetermined position when released by saidsupporting means for moving said switch member to an open circuitposition. Y,

9. A circuit breaker comprising a support, a contact arm pivoted on saidsupport, an operating member, a spring connected to said contact arm andsaid operating member for biasing said operating member and said arm toclosed circuit positions and said operating member to a second position,supporting means movable upon a change in current conditions fornormally holding said operating member in an operating position againstits bias to said second position, but releasing said operating memberupon the occurrence of a predetermined current in the circuit controlledby said contact arm, and means responsive to movement of said operatingmember to said second position for actuating said contact arm to an opencircuit position.

10. A circuit breaker comprising a support, a contact arm pivoted onsaid support, an operating member for said contact arm. an over-centerspring connected to said contact arm and said operating member for basing said operating member and said contact arm in either open circuitpositions or closed circuit positions and continuously biasing saidoperating member to a thirdp sition. supporting means movable upon .achange in thermal current conditions for normally holding said operatingmember in an opcrating position against its bias to said third position,and means responsive to movement of said operating member to said thirdposition when released by said supporting meansfor moving said contactarm to its open circuit position.

11. A circuit breaker comprising a base, a contact arm pivoted on saidbase, an over center spring having one end connected to said arm, an

operating member connected to the other end of said spring and movableto operate said con tact arm between two positions with a snap action, asupport for said member pivotally mounted on said base, currentresponsive means normaliy securing said support in a predeterminedposition to tension said spring, and means responsive to movement ofsaid support by said spring when said support is released by said current responsive means for moving said contact arm to its open circuitposition.

12. A circuit breaker comprising a base, a con-- tact arm pivoted onsaid base, an over-center spring having one end connected to said arm,an operating member connected to the other end of said spring andmovable to operate said contact arm between closed and open circuitpositions with a snap action, a support for said mem" ber movablymounted on said base, load responsive means for normally holding saidsupport in position to tension said spring, and means responsive tomovement of said support by said spring when said support is released bysaid load responsive means for moving said contact arm to its opencircuit position, and a projection on said operating member engagingsaid base when said operating member is moved to open circuit positionafter operation of said load responsive means for returning said supportto a position to be held by said overload responsive means.

13. A circuit breaker having a support, a switch member hinged to saidsupport, a hinged member having an arm for engaging said switch memberto move it toward an open circuit position, an actuating member pivotedto said hinged member and having an extension fulcrumed on the support,a toggle acting spring connecting said actuating member and said switchmember, means releasable upon an overload for holding said hinged memberin its nor-- mal position under normal load conditions, said springmoving said actuating member, said hinged member and said switch memberto an open circuit position when said holding means is released upon anoverload, said actuating member being tiltable about said fulcrum toreset the holding means.

14. A circuit breaker having a frame, a contact pivoted to said frame, akick-ofi member pivoted to said frame, and engageabie with said contact,an actuator, means pivotally connecting said actuator and said kick-oilmember, a

spring between said actuator and said contact, a current responsivedevice normally restraining pivotal movement of said i-ticit flfi memberbut actuated by abnormal current conditions to permit such movement,whereby the pivot connection between the actuator and iriciooif memberis normally stationary so that pivotal zrovement of the actuator willcause the spring to move the contact to on and oft" positions and whenthe current responsive device permits pivoting oi the tick-off memberthe spring will cause movement of the actuator pivot, thus pivoting thekick-pit member to engage and move the contact to of! position, means onsaid kick-off member and said. frame cooperating to limit movement 01the actuator when the kick-off is released, and means on the actuatorengaging said kickmfi member whereby pivotal movement of said actuatorwill move said kick-off member against the action of said spring torestore the member into restraining relation with said currentresponsive device,

15. A circuit breaker having a frame, a con tact pivoted to said frame,a kick-off member pivoted to said frame and engageable with saidcontact, an actuator pivoted at one end to said kick-cit member, aspring between the other end of the actuator and the contact, a currentresponsive device normally restraining pivotal movement of said kIClbOfimember but actuated by abnormal current conditions to release saidmember, whereby the pivot oi! the actuator on the kick-off member isnormally stationary so that movement of the actuator will cause thespring to move the contact to on and off positions and when the currentresponsive device releases the kick-off member the spring will causemovement of the actuator pivot, thus pivoting the kick-01f member toengage and move the contact to "oil?" position, means on said kick-oilmember and said frame cooperating to limit movement of the actuator whenthe kick-off is released, said means including a portion on saidactuator, spaced from the actuator pivot, engaging said frame wherebypivotal movement of said actuator will move the actuator pivot away fromthe part of the frame engaged by the actuator portion and force saidkick-off member against the action of said spring to restore the memberinto restraining relation with said current responsive device.

RAYMOND N. ROWE.

